We've had a site go live on a trial license and now have the trial expiration notice on the homepage (!)

I'm trying to run the licensing page from the module's drop down, but just get an empty module with no fields or text so it appears I'm now unable to license this product.

The site is running on dnn 5.5. I've already tried using the module on a hidden simple page with no other modules but still the same problem
I saw the trial version was 55.06.06 and have since downloaded and installed 55.06.07 with the hope this would allow me to access the licensing page but it doesn't.